There is known an uninterruptible power supply device provided with a storage battery for continuously supplying power from the storage battery to equipment connected thereto during a predetermined time without causing power failure even if power from an input power source is interrupted. Techniques are developed for furnishing each customer with such a power supply device and supplying consumers with power when an abnormality occurs in supplying power due to power failure, shortage in remaining capacity of storage battery, or other reasons (see Patent Literatures 1 and 2).